Tracking an Errant owner/Landlord?

You should have received a site notice when the neighbour made it an HMO which has the landlord's details but you could ask the Council as well or ask the neighbouring tenants. Make sure you have adequate proof of the mice coming from his property into yours [putting trackers on all mice is an obvious first move] before any accusation, in case he suggests that both properties are highly likely to have mice nesting below, as is the case with most houses in the UK during winter.
Might be easier to just fill any holes in your property where mice can gain access inside. Behind the kitchen units, under skirting boards, etc.

Where there is food or food crumbs and tenants don't keep the place clean enough, i.e. regularly lifting upfood crumbs with a vacuum cleaner,and access to food, leaving unwashed dishes, leaving packets of crisps,biscuits, etc, mice will love to settle and breed in such places, so start with visiting your own tenants place to see if they follow basic hygiene and keep the place free of any food,all food should be locked up in cupboards inaccessible to mice.

Things like rice, sugar, lentils, grains, should all be stored in glass or metal jars, not in plastic or paper bags.

If the property is licensed, there may be a register on the Council website. If not, you could spend £3 and find the name of the owner from the Land Registry. That may not be the landlord, but it should get you closer.

I think contacting him directly is a very reasonable thing to do, and if he is a responsible landlord he should appritiate it and deal with it quickly. Land registry is £3 to get the owner.

However, from the limited info you have provided, maybe he is not so responsible, if you struggle, a call to environmental health will make it the council's problem to sort and will highlight the property to the council and may bring other issues to the surface...i.e. HMO licensing etc. You have quite a lot of leaverage.

If you want to trace the owner of the property next door then as said by the above post it can be found online for only £3 on a government site, or if its a HMO with a licence the council hold lists of HMO owners for everyone to view. But vermin of this kind are everywhere so my advice is to call in the council to deal with it, and advise you on the places they may be getting in. My HMO's are in a famous and middle class city but the problem with both mice and rats are epidemic. I have just recently had mice in one of my HMO's. The Council charged £85 and faithfully visited three times with arrangement through the tenants. They advised me to cover my air bricks with mesh. All is good so far. I have been charged huge sums by commercial firms to get rid of vermin and they have refused to revisit even though it was part of their deal.

Would you consider it a witty thought if in the meantime you and your tenant invested in a large fierce and permanently hungry cat?

mice are nice

stop feeding them if you dont like them

I got a text last year from a new tenant to inform me that the flat had a spider problem. In the 10 days that she'd been there she'd seen a spider in her bedroom twice and one in the bathroom once. She wasn't bothered about the mice though.

foxes eat mice

Reply to the comment left by Lindsay Keith at 09/12/2020 - 12:29
A Jack Russell would be good. But not if poison is being used.